Canned metal charge



Oct. 12, 1965 J. w. GAYDOS CANNED METAL CHARGE 2 Sheets-Sheet 1 Filed Feb. 12, 1962 FIG 2 IN V EN TOR.

JAMES W GAYDOS Oic s.

Oct. 12, 1965 J. w. GAYDOS CANNED METAL CHARGE 2 Sheets-Sheet 2 Filed Feb. 12, 1962 FIG: 5

R mm A We mw S E M M BY Lush- M )cim w United States Patent "ice 3,211,286 CANNED METAL CHARGE James W. Gaydos, 23475 Shelburne Road, Shaker Heights, Ohio Filed Feb. 12, 1962, Ser. No. 172,653 2 Claims. (Cl. 206-84) The present invention relates generally to metal casting and more particularly to a method of die casting as well as the apparatus for accomplishing the same, and in addition, relates to a canned metal charge for use in this process and apparatus.

The size and generally complex nature of die castings such as aluminum for example, as presently designed to suit industrial demands, have been a distinct problem for the die casting industry. The heretofore described castings have started a trend toward the use of very large die casting machines and casting refinements such as the vacuum process, automatic ladling devices and automatic charge furnaces.

In general, the vacuum processes are based on the concept of removing air and gases from the die cavity area prior to the injection of molten metal into the die cavity area. These processes have in many instances proved to be erratic and at times quite expensive to operate.

Attempts have also been made to combine the vacuum processes with a form of automatic ladling in which atmospheric pressure is utilized to force the molten metal into the charging chamber of the die casting machine.

In the use of these methods, the molten metal is actually in a state of being de-gased under vacuum, and these gases are included in the casting as the metal is forced into the die cavity areas.

In the conventional cold chamber die casting nonvacuum) the charging chamber or cylinder is normally filled to approximately one-half to two thirds of its capacity before the metal is forced into the die cavity areas. Since this represents only a partial capacity of the charging chamber, the remaining volume of air and/ or gases is trapped and forced into the die castings along with the molten metal. Other factors create die casting variables, one of which is pressure loss due to friction between the plunger and charging chamber.

It will be seen from a review of the hereinabove given versions of known die casting methods, that an object of the present invention is to provide a die casting method and apparatus which will greatly cut down if not eliminate the amount of foreign gases which are included in the casting.

Another object of the present invention is to provide a method and apparatus for die casting wherein there is little if any gas entrapped in a partially filled charging chamber.

Another object of the present invention is to provide a die casting method and apparatus wherein there are no sludge or inclusions in the finished casting due to contaminated or oxidized metal which is common in manual ladling, automatic ladling, or metered furnace type charges.

Another object of the present invention is to provide a die casting method and apparatus with a much more uniform pressure for each molding shot in that there is little pressure loss due to galling or dragging of the plunger within the charging chamber.

Another object of the present invention is to provide a decreased chamber length, plunger stroke, and plunger cylinder, due to the condensed volume of the canned metal charge therein since there is no partial filling of the charging chamber.

Another object of the present invention is to provide a 3,211,286 Patented Get. 12, 1965 method of filling a container under vacuum with a metal which is to be ultimately cast.

Another object of the present invention is to provide a canned metal charge for use in casting.

Another object of the present invention is to provide an apparatus for die casting which includes a die and a charging chamber in combination with a plunger which is movable on a casting stroke and a return stroke along with a cutter in the charging chamber whereby when a canned metal charge is positioned in the charging chamber and the plunger moves on the casting stroke, the canned charge is brought into contact with the cutter means and the canned metal is opened and the metal is the canned charge is forced into the die cavity.

Another object of the present invention is to provide a die casting apparatus and method wherein a uniform charge of metal is provided for each casting or injection stroke.

Another object of the present invention is to provide a process for die casting which includes providing a canned metal charge with the metal in the can being in a molten state and placing the canned charge in a charging chamber and pushing the canned charge into contact with cutter means to open the canned charge and thereafter forcing the molten metal into a die cavity.

Other objects and a fuller understanding of this invention may be had by referring to the following description and claims, taken in conjunction with the accompanying drawings, in which:

FIGURE 1 is a side elevational view in section of the die casting apparatus of the present invention illustrating only a portion of a die casting apparatus to carry out the method of the present invention;

FIGURE 2 is a view similar to FIGURE 1 but showing the parts of the apparatus in a slightly different position from that shown in FIGURE 1;

FIGURE 3 is a view similar to FIGURES 1 and 2 but showing the parts in still another position;

FIGURE 4 is a view similar to FIGURES 1 to 3 but showing the parts of the apparatus in still a further position;

FIGURE 5 is a schematic view of an apparatus for preparing the canned charge of metal which is utilized in the apparatus and method of the present invention; and

FIGURE 6 is an enlarged cross sectional view showing the canned metal charge of the present invention.

Referring to FIGURES 1 through 4, the apparatus which is utilized to accomplish the casting of the present invention has been indicated generally by the reference numeral 10, and includes in combination a machine platen 12 to which is suitably affixed a die. A movable or ejector platen would also normally be included, however, this has not been illustrated because it will be appreciated by those skilled in the art. The general overall construction of the machine such as the mechanism forvmoving the various parts, separating the die parts, etc. may be substantially conventional such as machines made by Lester-Phoenix, Inc., Cleveland Automatic Machine Company and Reed-Prentice Corporation. The overall construction may be on the order of that illustrated in US. Patent Nos. 2,112,342 and 2,309,460. The die is comprised of a cover die half 14 and an ejector die half 15. The mating faces of the die halves 14 and 15 are provided with wall means which define a die cavity 17 which is in the shape of the finished part which is to be cast. The die cavity is produced in the conventional manner known to those skilled in the art. A charging chamber 19 is provided which is generally cylindrical in nature and a first end portion 20 of the charging chamber 19, as shown in FIGURES 1 through 4, extends through the cover die half to the ejector die half 15. A second end portion 21 of the charging chamber extends exteriorly of the die through the machine platen 12. A cutter member 23 is located at the first end portion 20 of the charging chamber and in the embodiment shown is secured to the ejector die half 15. A plunger member 25 is adapted to move in the charging chamber 19 between the first and second end portions thereof. Movement of the plunger member from the second end portion to the first end portion of the charging chamber may be referred to as a charging or injection stroke and movement of the same from the first to the second end portion may be said to constitute a return stroke. Wall means generally indicated by the reference numeral 27 may be said to define a loading opening for the reception of a canned charge of metal indicated generally by the reference numeral 30. The wall means 27 may be said to be between the first and second end portions 20 and 21 of the charging chamber even though in the embodiment of FIGURES 1 through 4 it is shown as being closer to the second end portion 21.

The canned charge of metal 30 will be described in more detail hereinafter, but for the present, comprises a metal container 32 preferably of steel of the deep drawing variety or equivalent with a molten metal 34 contained therein which is to be used in making up the final casting. The steels for the container may be described as low carbon steels, any of which would fall within the analysis of 0.15 maximum carbon and :25 to 0.50 manganese and further identified as SAE numbers 1008 to 1015. These examples are made solely by way of illustration since it will be apparent that the construction of the container may vary widely from the standpoint of material of construction and physical shape. Examples of the molten metal 34 may include aluminum, zinc, magnesium or brass, and might generally be classified as non-ferrous metals and alloys thereof. The canned charge 30 with the metal 34 therein in the molten state is introduced into the charging chamber 19 as shown in FIGURE 1 and the plunger member 25 is started on its injection stroke which moves the left end of the canned charge into engagement with the cutter member 23 which cuts an opening therein as shown in FIGURE 2. The dot dash line position 35 shown is merely for the purpose of illustrating introduction of same into the chamber 119. Further movement causes the container 32 to be accordi oned generally into the position shown in FIGURE 3 which in turn causes the molten metal contained in the container to be forced into the die cavity 17 through passageway means 36 between the charging chamber and the die cavity.

After the metal has been forced into the die cavity and solidifies, the ejector die half 15 opens to the position of FIGURE 4 .and the plunger member 25 moves through the cover die half 14 to completely eject the accordioned container 32 or biscuit as it is sometimes referred to. Conventional ejector pins 38 are provided, and power means 40 have been indicated schematically (FIGURE 4) for the purpose of moving the ejector pins 38 into engagement with the finished casting to eject it from the die.

FIGURES S and 6 respectively indicate generally how the canned charge 30 is prepared and one embodiment of the finished canned charge. The canned charge in FIG- URE 6 comprises the metal container 32 with the metal 34 contained therein and with a cover member 43 closing the open end of the container. The metal 34 is indicated in this FIGURE 6 as having solidified. The inside surface of the cover member 43 as well as the container 32 are provided with a coating 45 to prevent the pickup of the metal from which the container 32 is made by the metal 34 which is to constitute the finished casting, The thickness of the coating 45 in FIGURE 6 has been exaggerated to facilitate its illustration and in FIGURE has not been shown at all. A suitable example of this coating is one part calcium carbonate, one part sodium silicate and two parts water. This coating may be brushed or sprayed on the inside surface of the container and cover member prior to the metal 34 being introduced in the container. In some instances the coating may be omitted because the pickup of the container 32 met-a1 is negligible.

FIGURE 5 illustrates generally an apparatus which may be used to fill and close the container 32. This apparatus includes a vacuum chamber 47 in combination with a vacuum pump steam ejector or other method for inducing a vacuum 48 and vacuum accumulator 49 connected by way of conduit 50 through a vacuum valve 51 to the vacum chamber 47. A vacuum release valve 54 is provided for releasing the vacuum within the chamber 47 when desired, and a metal supply 56 from a melt or vacuum melt is indicated as associated with the vacuum chamber 47 and has a spout 57 which may be moved relative to the container 32 contained within the vacuum chamber. Also provided in the chamber is a sealing cylinder 59 and piston 60 which is adapted to be moved up and down to bring a cover member 43 carried on the end of rod 61 into engagement in the opening in the top of the metal container. A mechanism 63 is also illustrated only schematically and is for the purpose of crimping the upper edge of the container 32 over the cover member 43. In general, the container 32 with the coating 45 thereon is placed in the vacuum chamber as shown and the vacuum release valve 54 is closed and the valve 51 is opened and by means of the vacuum accumulator 49 and vacuum pump steam ejector or other method for inducing a vacuum 48, a vacuum is produced in the vacuum chamber 47. The vacuum produced in the chamber may vary but is preferably on the order of 25 to 29 plus inches of mercury. After the vacuum is drawn, the spout 57 is moved into position and the container is filled to the desired height with the metal 34. After this, the spout is moved out of position and the cover member 43 is brought into the opening in the top of the container by means of the sealing cylinder 59, piston 60 and rod 61. The mechanism 63 is actuated to provide an air tight seal between the cover member and container. It will be appreciated by those skilled in the art that other modifications of the filling apparatus are possible such as a continuous process and other means of closing the container after it is filled with metal.

The canned charge 30 may be used directly after filling if so desired, or the canned charge may be cooled and stored until it is desired to use the same If the charge is stored for a period of time until the temperature drops below the melting point of the metal 34 (FIGURE 6), it is necessary to re-heat the canned charge to bring the metal 34 up to its casting temperature (FIGURES 1-3) or, in other words, to a temperature where it is in a molten state. This temperature is on the order of 1250 to 1300 degrees Fahrenheit for aluminum, 800 to 815 degrees Fahrenheit for SAE No. 903 or 905 Zinc, 1250 to 1300 degrees Fahrenheit for magnesium, and for the various alloys the casting temperature will be known and appreciated by those skilled in the art. These temperatures fall sufiiciently below the melting point of the contamer, and as a result, the invention provides in effect a solid outside container with a molten metal therein for use in the die casting method and apparatus of the present invention.

It will therefore be appreciated by those skilled in the art that by means of the herein disclosed method, apparatus and article of manufacture, the objects as set forth are carried out.

Although this invention has been described in its preferred form and preferred practice with a certain degree of particularity, it is understood that the present disclosure of the preferred form and preferred practice has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts and steps may be resorted to without departing from the spirit and the scope of the invention as hereinafter claimed.

What is claimed is:

1. An article of manufacture comprising a steel container, a non-ferrous metal at least partially filling said steel container and being in direct contact with the walls of said steel container, said non-ferrous metal being selected from the group consisting of aluminum, zinc, and magnesium, a cover member closing said steel container, said steel container being under a vacuum.

2. An article of manufacture comprising a metal container, a different metal at least partially filling said metal container and being in direct contact with the walls there- .of, said metal at least partially filling said metal container being selected from the group consisting of aluminum, zinc, and magnesium, a cover member closing said metal container, said metal container being under a vacuum.

References Cited by the Examiner UNITED STATES PATENTS 666,452 1/ Oil Zucker 206-84 1,344,664 6/20 Wander 2-068'4 2,712,384 7 55 Corneil 20684 2,848,770 8/ 58 Schuchardt 2 268 2,848,800 8/5 8' Maloney et al.

2,877,088 3/59 Wellborn et al. 206-84 2,971,230 2/61 Coleman et .al. 2268 3,057,474 10/62 Litz 206-84 THERON E. CONDON, Primary Examiner.

RAY K, WINDI-IAIN, Examiner. 

1. AN ARTICLE OF LMANUFACTURE COMPRISING A STEEL CONTAINER, A NON-FERROUS METAL AT LEAST PARTIALLY FILLING SAID STEEL CONTAINER AND BEING IN DIRECT CONTACT WITH THE WALLS OF SAID STEEL CONTAINER, SAID NON-FERROUS METAL BEING SELECTED FROM THE GROUP CONSISTING OF ALUMINUM, ZINC, AND MAGNESIUM, A COVER MEMBER CLOSING SAID STEEL CONTAINER, SAID STEEL CONTAINER BEING UNDER A VACUUM. 